Our research efforts have been directed towards two goals: 1) Treatment of patients with severe Gram negative bacteremia with J5 antiserum. 2) Examination of the protective properties of J5 antibody against Pseudomonas aeruginosa bacteremia. BIBLIOGRAPHIC REFERENCES: Braude, A.I. Opposing Effects of Immunity to Endotoxin: Hypersensitivity Versus Protection. Ed. B. Urbaschek, R. Urbaschek, E. Neter, p. 69-74, Springer-Verlag, New York-Wien, 1975. Ziegler, E.J., Douglas, H., and Braude, A.I., Experimental bacteremia due to Pseudomonas in agranulocytic animals. Journal of Infectious Diseases, Vol. 130:S145, 1974.